Calculating mechanism for calculating machine

ABSTRACT

A calculating mechanism comprising a credit balance transfer means in which the negative or positive symbols of the value memorized in the calculator are inspected, and an add and subtract control linkage for bringing the accumulator gears alternately in mesh with the actuator racks.

United States Patent Toshlkl Kawamura Narashlno-shl;

Tohru Ohneda, Funabashl-shl; Yasuakl Nomura, Tokyo; Klkuo Taguchl, Funabashl-shl, all 0! Japan [72] Inventors [21 I App]. No. 824,13l

1221 Filed May I3, 1969 [45] Patented Nov. 16,197]

(73] Assignee Kabushlkl kalsha llattorl Tokelten C huo-ku, Tokyo, Japan [32] Priorities May [8, I968 [33] Japan May 27, [968, Japan, No. 43/35627; May 27, 1968, Japan, No. 43135628 [54] CALCULATING MECHANISM FOR CALCULATING MACHINE 8 Clalms, 10 Drawing Figs.

[52] US. Cl 235/60.2, 235/60 TN I51] Int.Cl (106:21/04 [50] Field at Search 235/602. 60 TN [56] References Cited UNITED STATES PATENTS 2,705,106 3/1955 Westinger et al. 235/602 3,281.06) 10/1966 Bullock .i 235/60 3,315,885 4/1967 Sato etal. 235/60 3,384,301 5/1968 Berkman et a1 235/60 Primary Examiner-Stephen l. Tomsky Anorneys- Robert E. Burns and Emmanuel .I. Lobato ABSTRACT: A calculating mechanism comprising a credit balance transfer means in which the negative or positive symbols of the value memorized in the calculator are inspected, and an add and subtract control linkage for bringing the accumulator gears alternately in mesh with the actuator racksv PATENTEDNUV 1B l97l 3,620,445

SHEET 2 0f 5 PATENTEUnnv 16 l97l SHEET 3 0F 5 PATENTEDNUV 16 Ian SHEEI UF 5 PATENTEDNUV 1s nan SHEET 5 BF 5 CALCULATING MECHANISM FOR CALCULATING MACHINE BACKGROUND OF THE INVENTION This invention relates to improvements in calculating mechanism for calculating machines that are utilized for addition and subtraction, which mechanism comprises a credit balance transfer mechanism and an add and subtract control linkage for the add and subtract accumulator gears, respectively.

BRIEF SUMMARY OF THE INVENTION This invention provides a novel, improved calculating mechanism for a calculating machine.

According to one feature of the present invention, a calculating mechanism for a calculating machine comprising a credit balance transfer mechanism including means for transmitting the motion of the column transfer lever in the accumu lator unit on the high side to the column transfer lever in the accumulator unit on the low side and a symbol setting unit having a square tooth wheel adapted to be rotated by the column transfer motion of the column transfer lever in the accumulator unit on the high side and a symbol inspecting element engageable with the square tooth wheel in order to indicate the change in the negative and positive symbols of the value memorized by the add and subtract accumulator gears; and an add and subtract control linkage for causing either of the add and subtract accumulator gears to engage selectively with the actuator racks depending on the desired operation of addition. subtraction, subtotaling or totaling is provided. Thus, the square tooth wheel can rotate smoothly and hence the symbol setting function can be achieved in a stabilized and accurate way.

According to another feature of the invention, a calculating mechanism for a calculating machine comprising a credit balance transfer mechanism including means for causing column transfer of the lowest digit by the column transfer action for the highest digit, and a symbol setting unit for indicating the change in the negative and positive symbols of the value memorized by the add and subtract accumulator gears; and an add and subtract control linkage having a geneva mechanism for rocking the accumulator gears thereby to cause either of the add and subtract accumulator gears to engage selectively with the actuator racks depending on the desired operation of addition, subtraction, subtotaling or totaling is provided. Thus, with the aid of the geneva mechanism, the accumulator gears and the actuator rack unit can be positioned in an accurate gearing relationship and, moreover, simplification of the overall construction can be realized.

It is an object of the present invention to provide an improved calculating mechanism for a calculating machine.

It is a further object of the present invention to provide a calculating mechanism for a calculating machine which can give positive and negative answers by accurate and quick adding and subtracting operations.

Another object of the invention is to provide a calculating mechanism for a calculating machine equipped with a credit balance transfer mechanism capable of operating smoothly and accurately.

Still another object of the invention is to provide a calculating mechanism for a calculating machine equipped with an add and subtract control linkage capable of ensuring precise engagement of the accumulator gears for adding and subtracting with actuator racks.

Other features, objects and advantages of the present invention will become apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view, partially broken away, of portions of a computing mechanism and a credit balance transfer mechanism according to the present invention;

FIG. 2 is an enlarged side view, partially broken away, of accumulator gears for adding and subtracting shown engaged with an actuator rack when the accumulator is set to 0" according to the present invention.

FIG. 3 is an enlarged side view of the first digit portion of the calculating mechanism of the present invention as view from the second digit portion;

FIG. 4 is a diagrammatic side view, partially broken away illustrating the gearing relationship between column transfer lever pawls and projecting cam teeth of the present invention;

FIG. 5 is an enlarged side view, partially broken away, of a part of a stop lever of the present invention;

FIG. 6 is an enlarged side view, partially broken away, of the engaging parts of the accumulator gear for subtracting and the yielding rack for the first column when the column transfer action to the highest digit has been performed according to the present invention;

FIG. 7 is an enlarged side view, partially broken away, of the engaging parts of the accumulator gear for subtracting and the yielding rack for the second or further column when the column transfer action to the highest digit has been performed;

FIG. 8 is an enlarged side view, partially broken away, of a column transfer lever in the accumulator unit of highest value and a part of a credit balance transfer mechanism according to the present invention;

FIG. 9 is an enlarged side view of parts of the credit balance transfer mechanism and the add and subtract control linkage of the present invention; and

FIG. 10 is an enlarged side view, partially broken away, of part of the geneva mechanism of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS COMPUTING MECHANISM The computing mechanism includes an accumulator having accumulator gears for adding and subtracting, yielding rack apparatus for engaging the accumulator gears, and a mechanism for effecting column transfer by a decimal system.

Referring to FIG. 1. an accumulator l includes accumulator gears for adding, i.e., 1a, 2b, 2c 2n and accumulator gears for subtracting, i.e., 3a, 3b, 3c 3n, which correspond, respectively, to the first column (for one-digit figures second column (for two-digit figures), third column (for three-digit figures) up to the n-th column. These accumulator gears for adding and subtracting are rotatably mounted on common gear shafts 4 and 5, respectively, the pair of accumulator gears for adding and subtracting for the same figure being in mesh with each other. Shaft 4,5 are fixedly secured at both ends to accumulator gear holders 6, which in turn are fixed to a center shaft 7. Accordingly. the rotation of the center shaft 7 results in the rocking of all of the accumulator gears for adding and subtracting. On the higher-column sides of the accumulator gears for adding, i.e., Zen-2n and the gears for subtracting, i.e., 3a-3n these are secured to the shafts 4 and S projecting cam teeth for adding, i.e., Ila-8n and projecting cam teeth 90-9" for subtracting, respectively.

The accumulator gears for adding and subtracting have l0 teeth each, as illustrated particularly in FIG. 3. The teeth of the add accumulator gears 20-211 and the subtract accumulator gears Ila-3n are such that those which correspond to the projecting add cam teeth -81: and the projecting subtract cam teeth 9a-9n are the teeth that memorize the FIG. and the following teeth, in the counterclockwise order, are those that memorize the FIGS. "1, 2" and so forth up to 9." For a better understanding of this arrangement, the teeth of the add and subtract accumulator gears are shown as marked with the figures to be memorized.

Elongated racks Illa-Ion which correspond to the first to in th columns are formed with guide slots II and 12 each of which extends longitudinally of the elongated racks. Through the slot 11 is slidably inserted a rod 13, which is secured at both ends to the side plates 5!. Through the other slot I2 is slidably inserted a transverse bar [4, both ends of which extend through the guide slots 107 formed in the side plates 51. A motor, now shown is connected to the bar 14 to drive the bar in the conventional manner. Coil springs 160-1601 are connected at one end to fixed pins l5a-l5n and constantly urge the racks loo-:1 in the advance direction indicated by the arrow A thereof. Along the side of racks l0a-l0n are slidably attached elongated yielding racks l'la-l'ln with pins 19 fitted in slots l8 formed in the racks Illa-10a. Further, the yielding racks 17a-l7n are urged by springs 20a-20n in the rearward direction indicated by the arrow B with respect to the racks 10040.

The construction of the column transfer mechanism will now be described. Referring to FIGS. 1 and 3, stop levers 210-2! corresponding to the first to the n-th columns are rockably mounted on a stop lever shafl 22 which is fixedly secured at both ends to the side plates 51,5], and are urged in the counterclockwise direction, as viewed in FIG. I and indicated by the appropriate arrows, by coil springs 23a-23n connected at one end to a respective one of the levers and at the other used to a fixed pin. These stop levers have arms 240-24 and 25a-25n, i.e., at least two arms for each lever. An car at the front end of each of the arms 24a-24n is adapted to abut the rear end of each of a respective one of the yielding racks l7a-l7n, while an ear at the front end of each of the arms 250-25" is adapted to engage each of a respective one of column transfer levers presently to be described. On the left end of the stop lever shaft 22 (FIG. 1) is rockably mounted a ratchet lever 26 having an arm 28 and a fork 29 and which is urged in a counterclockwise direction by a spring 27. An car at the front end of the arm 28 is adapted to engage with the column transfer levers described below.

Elongated column transfer levers 30a-30n for the first to an-th columns are rockably mounted intermediate their ends on a shaft 31 that is fixedly supported at both ends by the side plates SL5], the levers Sun-30!: are urged in the clockwise direction as viewed in FIG. 1 by springs 32a-32n that are secured at one end to the levers and at the other end to a fixed pin. On the front part of the column transfer levers 30a-30n there is formed column transfer add lever pawls 33a-33n which are engageable with the projecting add cam teeth 80-811 and column transfer subtract lever pawls 34a-34n which are engageable with the projecting subtract cam teeth 9a-9n. When an accumulator gear for adding or subtracting is in mesh with a yielding rack l7a-l7n, the "figure" of the tooth out of the 10 teeth of the gear that corresponds to the particular column transfer lever pawl represents the figure which is memorized by the gear. For example, when the tooth "8 of the gear faces the column transfer lever pawl, it means that the particular gear has "8" in memory. The position of an accumulator gear thus facing or matching with alone column transfer lever pawl is hereinafter referred to as a memorized figure indicating point. The column transfer levers Mia-30:1 are formed, at the rear part thereof, with lugs 35a-35n which are engageable with the arms 25a-25n of stop levers. These lugs 3$a35n are in mesh with the arms 25b-25n of stop levers lib-2|, each column transfer by one column, coaction is, the lug 35a of column transfer lever 30a for the first column meshes with the arm 25b of stop lever 21b for the second column, the lug 35m of column transfer lever 30m meshes with the arm 25m of stop lever 2111. However, the lug 35a of column transfer lever 30" for the highest column alone engages with the arm 28 of ratchet lever 26, and the arm 25:: of stop lever 2la for the first column is engaged by the lug 38 of column transfer lever 36 for the "0 digit that is rockably mounted on the shaft 3] and is pulled in the clockwise direction (FIG. I) by a spring 37. Column transfer lever 30" for the highest digit is linked by a transfer lever 39 to the 0" column transfer lever 36 for coaction therewith, as can be seen more clearly in FIG. 1.

A carriage 40 shown in FIG. 3 is of a well-known type having a multiplicity of carriage pins 42 that engage the lugs 410-41 formed at the rear ends of the racks l0a-l0n thereby to control the motions of those racks. A printing mechanism 43 shown is also of a conventional design, including medial gears 45a-45n in mesh with teeth alone a-44n provided on the upper edge (P16. 3) of the racks 10a-l0n. dial wheel memblies 470-4714 in mesh with the medial gears and which are provided with type along the circumferences thereof, and a platen 48 adapted to be brought into and out of contact with the dial wheel assemblies with the aid of conventional rocking mechanism. column transfer coaction The operation of the computing mechanism constructed as set forth above will now be described specifically in connection with the addition of values 7" and "8" by way of example.

The positions of parts before the operation (which are hereinafter referred to as the original positions) are such that the stop levers 2la-21n with their arms 2412-2411 keep the yielding racks I7a-17n from any movement in the rearward direction B and with the other arms 250-25): prevent the clockwise rocking of the column transfer levers 30a-30n, while the racks Illa-10a are kept in positions one tooth behind the yielding racks l'la-l7n by means of the transverse bar 14. Accumulator gears 2a2n and 30-31: of accumulator l are not, at this point, in mesh with the yielding racks l7a-l7n.

When the operator presses a key marked 7" of a conventional value-entry means (not shown), a carriage pin 42 corresponding to the key is pressed down. Next, the operator presses a conventional add key means (not shown) and the addition instruction is transmitted through a conventional transmitting means (not shown) to an add and subtract control means for the accumulator gears to be described later. Also, the manipulation of the add key enables a motor (not shown) to start and drive the transverse bar 14 in the direction indicated by the arrow A in FIG. 1 toward which the racks are urged. Accordingly, the rack 10a for the first column is urged forward in the direction A by the spring to a point advanced from the original point by 8 teeth, where the carriage pin 42 thus depressed engages with the lug 41a. Meanwhile, the racks l0b-l0n for the second and further columns remain stationary because they are kept from advancing by an 0" position stop lever of conventional design (not shown) provided on the carriage 40. By the advance of the rack 10a for the first column, the printing mechanism 43 is actuated to print the figure 7" on paper positioned between the dial wheel assemblies 470-47" and the platen 48. Upon completion of the printing, the add accumulator gear 20, out of the gears for adding and subtracting whose gearing is shifted by an add and subtract control means to be explained later, comes into mesh with the yielding rack l7a. When no figures has been activated in the memory bank of the accumulator l, as shown in FIG. 2, the actuating side 8p of the projecting cam tooth 8a of the add accumulator gear 2a is in contact with the stop side 33p of the pawl 33a of the column transfer lever 300. Now, as the transverse bar 14 moves in the rack-retracting direction as indicated by the arrow B in FIG. I, both the rack [0a and yielding rack "0 move backward. When the add accumulator gear 20 in mesh with the yielding rack has turned by 7 teeth, corresponding to the figure 7," the yielding rack 17a is stopped by the stop lever 21a and therefore the accumulator gear 2a is also kept from turning farther. Transverse bar [4 returns to the original position where the rack l0a has moved back by another tooth, and remains stationary. By an add and subtract control means the add accumulator gear 20 is released from meshing engagement with the rack 10a. in the manner described, the figure 7" is now memorized by the add accumulator gear 20 for the first column.

The value-entry operation for adding "8" to the figure already memorized is as follows. In the same manner as set forth above, the figure key 8" is pressed and the figure 8 is printed and then the add accumulator gear 20 is brought into meshing engagement with the yielding rack [7a. In this initial gearing, because the figure "7" is already memorized by the add accumulator gear 20 for the first column of the accumulator. the tooth 7" of the accumulator gear meshes with the corresponding tooth of the column transfer add lever pawl 33a of the yielding rack 17a. In the same manner as above explained, the transverse bar 14 moves in the retracting direction B and the yielding rack 17a moves backward by three teeth, when, as shown in FIG. 3, the actuating side 8:; of the projecting cam tooth 8a of the add accumulator gear 20 meshes with the stop side 33q of the column transfer lever pawl 33a in a manner that is contrary to the combination as described above. As the yielding rack 17a continues to recede, the stop side 33q is urged upward by the actuating side Sq, with the result that the column transfer lever 30a is rocked clockwise as viewed in FIG. 3 and its lug 35a is disengaged from the arm 25b of stop lever 2]!) for the second column. Stop lever lib thus set free is rocked clockwise by the spring 23b as shown in FIG. 3 and is demeshed from the rear end of yielding rack 17b for the second column. As a consequence, the yielding rack I7b under the urging of the spring 20b slides back by one tooth in the retracting direction B, whereby the accumulator gear for adding 2b for the second column that is in mesh with the yielding rack 17b is turned clockwise by one tooth. This means that a column transfer has been accomplished by the decimal system and the figure 1" has been memorized by the accumulator gear for adding 2b for the second column. After this column transfer action, the yielding rack l7a for the first column further recedes by five teeth, thus permitting the accumulator gear for adding 20 to memorize the figure 5, and then is kept in the receded position by stop lever 21b. As described hereinabove, the transverse bar 14 moves backward by another tooth to the original position where it remains still. Also, in the same manner as already described, the accumulator gears for adding 2a2n are demeshed from the yielding racks I'Ia-l7n. Thus, it is appreciated that the answer to the problem of 7 plus 8 is now in the memory of the accumulator because the accumulator gear for adding 2b for the second column has memorized the figure l" and the accumulator gear 2a for the first column has memorized the figure 5."

In the vent that a subtracting operation is desired, the add and subtract control means for the accumulator gear functions in response to the subtract command and enables the subtract accumulator gears 3a-3n to replace the add accumulator gears and come into mesh with the yielding racks I7a-l7n. For a column transfer a certain column subtract transfer lever pawl of a certain column transfer lever coacts with a particular subtract accumulator gear. These actions are similar to those involved in the adding operation. The rotation of the particular subtract accumulator gear is transmitted to the add accumulator gear engaged therewith, and the latter rotates in a direction opposite to that for addition. whereby the result of the subtraction is memorized by the add accumulator gear.

The improvements of the column transfer mechanism achieved in accordance with the present invention to realize the manufacture of smaller calculating machines with a higher calculating speed and with less component inertial forces than conventional machines will now be described in more detail. Because all of the column transfer levers Zion-30h, add accumulator gears 2a-Zn and subtract accumulator gears 3a-3n are of identical construction, the following description is made for the sake of simplification in connection with only one column transfer lever 30a and associated gears for adding and subtracting 20,30 by reference to FIG. 4. Lug 35a of the column transfer lever 30a and the arm 25b of stop lever 21b should be made disengageable from each other by either the projecting cam tooth 8a of the add accumulator gear 2a or the projecting cam tooth 9a of the subtract accumulator gear 3a. Thus, if the angle of rocking required by the lug 35a of the column transfer lever in disengaging itself from the stop lever Zlb is 0, the angle of rocking required by one lever pawl 33a of the column transfer lever is escaping from the pressure contact with the tooth 8a of the add accumulator gear is 0,, and the angle of rocking required by the other lever pawl 34a of the column transfer lever in escaping from the pressure contact with the tooth 9a of the subtract accumulator gear is 0,, then at least the relationship 0=0,=-0, should hold. In this example, therefore. the length of the projecting subtract cam tooth associated with the subtract accumulator gear 3 a is made less than that of the projecting add cam tooth 80, thereby to satisfy the above formula and permit the reduction in the length of the column transfer lever 300.

In another modification of the column transfer mechanism, the projecting cam teeth 8a,9a of the accumulator gears are made equal in length but the pawl 34a of the column transfer lever is made shorter than the other pawl 33a so that he column transfer lever may be reduced in length.

In still another modification of the column transfer mechanism, the projecting cam tooth 9a of the subtract accumulator gear and the pawl 34a of the column transfer lever are both shortened so as to provide a short column transfer lever.

Next, improvements in the column transfer mechanism to smooth the stop lever functions and thereby ensure accurate and positive column transfer actions will be described in detail. For simplicity the description is made by reference to FIG. 5 where there is shown a stop lever Zla associated with a column transfer lever 36 and a yielding rack 17a. The yielding rack 17a, urged backward by spring 200, is prevented from actually moving back because the rear end portion I08 thereof is in contact with the front end of the ann 24a of the stop lever 21a, but the line of action of pressure P (indicated by the arrow P in FIG. 5) applied by the rear end portion I08 of this yielding rack to the arm 24a is in the direction extending through the stop lever shaft 22. For this reason, the pressure is exerted against the shaft 22 transversely of the longitudinal axis thereof and no moment of rotation is produced in the arms 24a,25a of the stop lever and, accordingly, the force of friction produced by the front end of the arm 25a of the stop lever and the lug 38 of the column transfer lever 36 is so little that the two parts can be readily disengaged from each other.

CREDIT BALANCE TRANSFER M ECHA NISM The credit balance transfer mechanism comprises mainly interlocking means for causing the column transfer action of the accumulator unit of lowest value by the column transfer action of the accumulator unit of highest value, and means for indicating, with the aid of the column transfer action of the ac cumulator unit of highest value, whether a value memorized by the accumulator is positive or negative.

Referring first to FIG. 1, the column transfer lever for the highest digit 30!: and the column transfer lever for the lowest digit 36 are linked together by the transfer lever 39 in the manner as already described, so that the action of the column transfer lever Jon is accompanied by the action of the other column transfer lever 36. The column transfer lever for the highest digit 30!: carries out the column transfer action in either of two cases; first, when the value memorized by the accumulator 1 changes from positive to negative. and second. vice versa. It is this column transfer action of the lever for the highest digit 30!: that actuates the credit balance transfer mechanism.

The first examples of a column transfer action will now be described citing the instance of deducting 2" from the value +1 already memorized by the accumulator. Here it must be explained first that the +1 already memorized by the accumulator means that the accumulator gears for adding 20-2" of the accumulator indicate 0,0,0.....0,l" and the accumulator gears for subtracting 30-311 indicate 9,9,9.....9,8. Similarly, by the expression that the accumulator rnemorizes it is meant that the add accumulator gears Za-Zn are at 0,0,0 0.0 and the subtract accumulator gears Ila-3n are at "9, 9 ,9...9,9. The expression that the accumulator memorizes 0" means that the add accumulator gears Za-Zn stand at 9,9,9...9,9" and the subtract accumulator gears Ila-3n at 0,0,0...0,0, and the expression that the accumulator memorizes l means that the add accumulator gears 2a-2n stand at 9,9,9...9,8" and the subtract accumulator gears 3a-3n at 0,0,0...0,l

Now if the operator presses the figure key 2" and the subtract key. the subtract accumulator gear 30 meshes with the yielding rack 170 that has moved ahead by two teeth. The gearing state is such as shown in FIG. 6. where, because the accumulator has already memorized +l," the tooth 8" of the subtract accumulator gear 30 is in the memorized-value indicating point for the first figure, and the yielding rack 17a in the position retracted by two teeth. By the motions described the subtract accumulator gear 3a is also turned by two teeth, so that its tooth comes into mesh with the rack and the projecting subtract cam tooth 9a is caused to push up the column subtract transfer lever pawl 340. thus effecting the column transfer action above referred to. in the meantime, on the second column. the tooth 9" of the subtract accumulator gear 3b is in the memorized-value indicating point as shown in F IG. 7. and therejbre, as the yielding rack 17b for the second column is moved back by one tooth by the column transfer action on the first column. the subtract accumulator gear 3b is also turned by one tooth with the tooth 0" into mesh with the rack. and the projecting subtract cam tooth 9b pushes up the column transfer subtract lever pawl 34b. thereby effecting a column transfer action. As similar column transfer actions proceed in succession up to the n-th column, the column transfer lever 30:1 rocks with its lug 35n out of engagement with the arm 28 of the ratchet lever 26. This rocking of the column transfer lever for the highest digit 30:: is transmitted through the transfer lever 39 to the column transfer lever for the lOth column 36, which is thereby rocked to trip the stop lever Zia from the yielding rack 17a. thus permitting the latter to recede by one tooth. The recession of the yielding rack enables the subtract accumulator gear 3a for the first column to turn by one tooth with its tooth l into mesh with the rack. At this time. no column transfer action takes place. As the result of the operation for subtracting 2 from the value +l" in the manner above described. the subtract accumulator gears Ila-3n indicate 0,0,0...0,l while the add accumulator gears Za-Zn indicate 9.9.9...9,8" because they have rotated in the reverse direction the same amount of rotation as the subtract accumulator gears 3a-3n. Thus. the accumulator has memorized l." The column transfer action for the highest digit as above described leads to the rocking of the ratchet lever 26 by the spring. which in turn actuates the symbol setting unit. to be described later, of the credit balance transfer mechanism.

A second example of a column transfer action will now be described in conjunction with an instance where 2" is to be added to the value l already memorized by the accumulator. As described above. the fact that the accumulator memorizes "l means that the add accumulator gears Za-Zn stand at 9.9.9...9,8" and the subtract accumulator gears 3a-3n at 0,0.0...0,l.Accordingly. where "2" is to be added, the add accumulator gear 20 meshes with the yielding rack 17a moved forward by two teeth by a motion similar to that explained for the former example. In this gearing state. the tooth 8" of the add accumulator gear In for the first column is in the memorized-value indicating point. and the yielding rack l7a is receded by two teeth. By this motion the add accumulator gear 20 is also turned by two teeth with its tooth 0" in mesh with the rack and. at the same time. the column transfer add lever pawl 33a is pushed up by the projecting add cam tooth 8a. From then on the column transfer actions proceed in succession from the second to the n-th column in entirely the same manner as in the first example above described. until the teeth 0" of all the add accumulator gears 2a-2n come into mesh with the yielding racks. The rocking of the column transfer lever for the highest digit 30n is transmitted through the transfer lever 39 to the column transfer lever for the 10-": digit 36. thereby rocking the latter lever. which brings the tooth l of the add accumulator gear 2a into mesh with the yielding rack 17a. As a result of the operation for adding 2" to l in the manner described, the add accumulator gears 2a-2n indicate "0.0,0...0.l and the subtract accumulator gears 3a-3n indicate 9.9.9...9,8" as they have revolved in the reverse direction the same amount of rotation of the add accumulator gears Zia-2n. In other words. the accumulator I has now memorized +1. The column transfer action of the lever for the highest digit 30n causes rocking of the ratchet lever 26, which in turn actuates the symbol setting unit, to be presently described. of the credit balance transfer mechanism.

Now the symbol setting unit of the credit balance transfer mechanism will be explained with reference to FIGS. 1, 8 and 9. A ratchet wheel 49 to be driven by the ratchet lever 26 is fixedly secured to a credit balance shaft 50, which shaft extends through the space between the racks Illa-Ion and column transfer levers Silo-30!: and is rotatably supported by the side plates 51.5]. On one end of the credit balance shaft 50 protruding out of a side plate 51 is securely fixed a square tooth wheel 52 (FIG. I) having square lands on teeth and square recesses in an alternate and regular arrangement as a member for indicating the symbol of the value memorized by the accumulator. The number of teeth of the ratchet wheel 49 is twice that of the square tooth wheel 52. Accordingly, while the ratchet wheel 49 is moved ahead by one tooth. the square tooth wheel 52 turns from a tooth to a recess or contrariwise. Fork 19 of ratchet lever 26 is engaged with a follower pin 54 of a lever 53 which is rotatably mounted on the credit balance shaft 50. Onto this pin 54 is rotatably fitted a ratchet 55. which in turn is biased into engagement with the ratchet wheel 49 by a spring (not shown). A stopper 56 that permits the ratchet $5 to move the ratchet wheel 49 by one pawl and also a tripper 57 that is biased into engagement with the ratchet wheel 49 are fixedly supported by the side plate 5 1.

As the column transfer lever 30': is pushed up by the projecting cam tooth 8n or 9n. it rocks to disengage the lug 35" from the arm 28 of the ratchet lever 26 and thereby permits the lever 26 to rock counterclockwise (FIG. 8) by virtue of the spring 27. The rocking of the ratchet lever 26 moves the ratchet 55 to the position of the stopper 56, thus rotating the ratchet wheel 49 by one ratchet pawl. This rotation of the ratchet wheel 49 is transmitted through the credit balance shaft 50 to the square tooth wheel 52 thereby to rotate the wheel. When a tooth or land of the wheel 52 is opposed to an inspecting pin 84 of the add and subtract control linkage for the add and subtract accumulator gears to be described below. it means that the value memorized by the accumulator l is positive. When a recess of the wheel comes opposite to the inspecting pin. the value is negative. it thus follows that when a column transfer action for the highest digit is carried out as described above, the square tooth wheel 52 interlocked with the column transfer motion is shifted from a land to a recess or from a recess to a land. thus indicating. in other words. a shift of the symbol from positive to negative or vice versa. Gearing of accumulator gears and racks are governed by this controlling action of the square tooth wheel 52. Concerning this. a more detailed explanation will be made later in connection with the add and subtract control linkage.

The timing for the gearing between the accumulator gears and racks upon depression of the total key or subtotal key will now be described. Contrary to the case with the add key or subtract key. when the gearing is accomplished in the advanced rack positions as above described. the gearing when the subtotal key is pressed is achieved in the receded rack positions and the mating parts are disengaged only after they have been kept in gear while the racks move forward and backward. In the case of the total key. the gearing is achieved in the receded rack positions and maintained while the racks move forward. After disengagement at the advanced positions. the racks along retract.

The timing of these actions is controlled by cam means interlocked with the motor and by transmission means interlocked with the respective function keys. Since these means are conventional and known in the art. a detailed description is herein omitted.

ADD AND SUBTRACT CONTROL LINKAGE FOR THE ADD AND SUBTRACT ACCUMULATOR GEARS Referring to FIG. 9, an elongated transmit sliding plate 58 having three guide slots 59 extending longitudinally thereof is supported for sliding movement at an oblique angle by three guide pins 60 inserted through the guide slots. A substantially L-shaped transmit actuating plate 61 which acts upon a geneva mechanism is slidably associated with the transmit sliding plate 58 as three pins [09 provided thereon slidably fit in three guide slots 110 formed in the sliding plate 58 at right angles to the flat surfaces thereof. Transmit actuating plate 6| is constantly urged upward by a coil spring 64 which connects the lower end thereof to a rod 63 provided on the sliding plate 58, which rod extends through a slot 62 formed in the actuating plate. This actuating plate 61 has on its top end a follower member 65 bent at a right angle to receive the pushing force of the transmit lever presently to be described and also has on one side thereof a stopper piece 68 bent at a right angle to engage and stop either of transmit levers 66,67 of the geneva mechanism 94 to be explained below. This stopper piece 68 is engaged by a transmit pin 66 while the transmit actuating plate 6! is in the upper position, and is engaged by another transmit pin 67 while the plate 61 is in the lower position. A click lever 69 is rockably supported at an intermediate point by one of the pins 60, and a roller 7l fitted to one end of the lever 69 is biased into engagement with recesses Ill and H2 formed on the upper part of the transmit sliding plate 58 by a coil spring 70 connected by one end to the other end of the lever and by the other end to a fixed pin, while the sliding plate 58 reciprocates endwise.

A control lever 72 permits the transmit sliding plate 58 to reciprocate endwise and is rockably mounted intermediate its ends on a control lever shaft 73, with a fork 74 formed on one end thereof engaged with a follower pin 75 fixed to the sliding plate 58, while a pin [13 on the other end is engaged with a selection lever I14 slidably supported by the shaft 73. A group of cams 76 for rocking the control lever 72 include cams for adding and subtracting, subtotal cam and total cam, to which the revolutions of a motor (not shown) are transmitted. The selection lever I14 is moved selectively to a position to contact any of the group of cams 76 as the depressing motion ofa function key, e.g. add key, subtract key, total key or subtotal key, is transmitted thereto by the usual transmission means (not shown), and then acts as a medium for transmitting the driving force of the selected cam to the control lever 72.

A hook-shaped knocking lever 77 for shifting the position of the transmit actuating plate 61 with respect to the transmit pins 66,67 of the geneva mechanism is slidably supported at its root by a shaft 79, and is formed with a toe 78 at the front end for pushing the follower member 65 of the transmit actuating plate. This knocking lever 77 is rocked as the depressing motion of the subtract key is transmitted by conventional transmission means to a connecting bar 80 fitted to the lever. An inspecting lever 81 for inspecting the symbol of value relative to the square tooth wheel 52 is rockably supported intermediate its ends by a shaft 82. On the front end of the inspecting lever 84 is secured an inspecting pin 84, the front tip of which is slidably inserted into a slot 86 of guide plate 85 fix edly supported by the side plate 51, in such a positional relationship with the square tooth wheel 52 that when it slides the front tip of the pin contacts either a land or groove of the wheel. This inspecting pin 84 is driven as the depressing motion of the total key or subtotal key is transmitted by the usual transmission means to the connecting bar 83 on the other end of the inspecting lever 81. Additional means for driving the knocking lever 77 simultaneously with the inspecting pin 84 is provided, which comprises a lever 87 rockably supported by the shaft 79 and a connecting link 88 that rockably links the lever 87 with the inspecting lever SI. said knocking lever 77 being formed with a lug S9 for receiving the clockwise rocking of the lever 87, a spring 90 connecting the shaft 82 with the knocking lever 77, and a spring 92 is stretched between the inspecting lever 81 and a fixed spring stop 93, both springs pulling the knocking lever 77 and inspecting lever 8], respectively, counterclockwise as seen in FIG. 9.

Means for shifting the gearing of the add and subtract accu mulator gears 20-211 and 3a-3n with respect to the yielding racks l7a-I7n includes means 94 for rocking the add and subtract accumulator gears by the use of a geneva mechanism. Referring to FIG. 10 showing the rocking means with the add accumulator gears 2a-2n in mesh with the yielding racks l7a-l7, the transmit pins 66,67 are fixedly supported by a geneva driving gear 96 of the geneva mechanism rotatably mounted on a shaft 95. Geneva driving gear 96 has an arcuate cutaway part 98 and a pin I00, and a geneva wheel l0! engaged therewith is secured at its center of rotation to the center shaft 7 of the accumulator l and is formed with a recess I02 to engage with the pin I00 and arcuate cutaway parts 103,104 on both sides. Geneva wheel 101 is integrally connected with the accumulator gear holder 6 of the accumulator by connecting rods [05,106.

The operation of the add and subtract control linkage for the add and subtract accumulator gears is as described below. Before operation, as shown in FIG. 9, the knocking lever 77 is pulled counterclockwise by the spring 90, with the toe 78 kept away from the follower member 65 of transmit actuating plate 61. Accordingly, the transmit actuating plate 6| is kept in its upper position by spring 64, with the engageable member 68 facing the transmit pin 66. Meanwhile, in the geneva mechanism 94, the pin I00 of the geneva driving lever 96 is engaged with the recess 102 of geneva wheel ml, and both accumulator gears of the accumulator l are in the neutral positions, out of mesh with the yielding racks.

During an additive value-entry operation the knocking lever 77 remains inoperative. As the operator presses the add key of the machine in the state as shown in FIG. 9, the motor starts and the control lever 72 rocks clockwise with a timing in adequate response to the manipulation of the add key. This causes the transmit sliding plate 58 to slide in the advance direction A. Transmit actuating plate 6l that is moved in the same direction by the sliding plate 58 pushes with its engageable member 68 the transmit pin 66 of the geneva mechanism also in the same direction, whereby the geneva driving lever 96 is turned clockwise at a certain angle and the geneva wheel 10] is driven counterclockwise at a certain angle, to the position shown in FIG. 10. By the rotation of the geneva wheel 101 at a certain angle, the accumulator gear holder 6 of the accumulator is turned in the same direction thereby bringing the add accumulator gears 2a-2n into mesh with the yielding racks I7a-l7n. Thus, an additive operation is performed in the manner as already described. On completion of the calculation, the control lever 72 is rocked counterclockwise, FIG. 9, by the usual cam means and the sliding plate 58 is thereby restored to the original position.

In the case of a subtractive value-entry operation, the pressing of the subtract key pushes the connecting bar clockwise, FIG. 9. As a result, the knocking lever 77 rocks clockwise against the urging of the spring 90. with the toe 78 pushing down the follower member 65 of the transmit actuating plate 6I against the force of the spring 64. The transmit actuating plate 61 is thus pushed down to a point where the engageable member 68 faces the other transmit pin 67. As the control lever 72 rocks with a timing adequately in response to the manipulation of the subtract key and the transmit sliding plate 58 moves in the advance direction A, the actuating plate 61 pushes the transmit pin 67 of the geneva mechanism. with the result that the geneva driving lever 96 turns counterclockwise and the geneva wheel clockwise, both at certain angles where the subtract accumulator gears Zia-3n of the accumulator I come into mesh with the yielding racks l7a-l7n. Then, a subtractive operation is carried out in the manner as described hereinabove.

In the event of a totaling or subtotaling operation, the operator presses either the total key or the subtotal key. This motion is transmitted through the connecting bar 83 to the inspecting lever 81 and the lever rocks clockwise, FIG. 9, thereby pushing the inspecting pin 84 into contact with a land or recess of the square tooth wheel 52. If the accumulator 1 memorizes a positive value, the inspecting pin 84 contacts a land of the square tooth wheel 52. The movement of the inspectin g pin 84 into contact with the land of the wheel is transmitted through the connecting bar 88, lever 87 and lug 89 to the knocking lever 77, when the toe 78 rocks clockwise but slightly and not enough to push the follower member 65 of transmit actuating plate 61. For this reason, the add and subtract control linkage for the accumulator gears remains in the original position while the control lever '72 rocks with a timing in response to the total key or subtotal key, and therefore the add accumulator gears Za-Zn come into mesh with the yielding racks l7a-l7n and, in this state, the racks la-l0n move forward to print with the printing mechanism the total or subtotal value memorized by the accumulator. When the accumulator l memorizes a negative value, the inspecting pin 84 comes into contact with a recess of the square tooth wheel 52. The movement of the inspecting pin into the recess of the square tooth wheel causes the knocking lever 77 to press the follower member 65 of the transmit actuating plate 61, thereby urging the actuating plate 6] to a lower position where it faces the transmit pin 67. Since the control lever 72 rocks in this state in the manner as above described, the subtract accumulator gears 3a-3n come into mesh with the yielding racks l7a-l7n, and in this state the racks Illa-Ion advance to print with the printing mechanism the true value of total or subtotal figures memorized by the accumulator. The negative or minus mark is printed by the usual symbol-printing mechanism.

What we claim and desire to secure by Letters Patent is:

I. In a calculating machine, a credit balance transfer mechanism comprising an accumulator, a column transfer lever for each of a plurality of digits, means interconnecting the column transfer lever for the highest digit with the column transfer lever for the lowest digit, said column transfer lever for the highest digit being movable according to whether the value stored in said accumulator is positive or negative, a rotatable shaft, a ratchet wheel fixed on said shaft, means for converting movement of said column transfer lever for the highest digit into incremental rotary movement of said ratchet wheel and shaft, a rotatable member fixed on said shaft and having alternate lands and recesses, means for inspecting said rotary member for the presence of a land or recess at a predetermined position, said rotatable member being rotatable by said shaft, ratchet wheel and column transfer lever for the highest digit to position a land or a recess at said predetermined position according to whether the value stored in said accumulator is positive or negative and add and subtract control linkage controlled by said inspecting means.

2. A credit balance transfer mechanism according to claim I, in which said rotatable member is a gear having square teeth alternating with square recesses.

3. A credit balance transfer mechanism according to claim I, in which said inspecting means controls the selective engagement of an actuator rack with an add gear.

4. A credit balance transfer mechanism according to claim I, in which said inspecting means controls the selective engagement of an actuator rack with a subtraction gear.

5. A credit balance transfer mechanism according to claim I, in which said inspecting means comprises a movable lever, an abutment carried by said lever and means for moving said lever to bring said abutment into engagement with said rotatable member whereby said abutment engages a land or in a recess of said rotatable member according to the position of said rotatable member.

6. A credit balance transfer mechanism according to claim 5, in which said add and subtract control linkage comprises a geneva gear, a reci rocable sliding plate and an actuatin plate carried by sar shdmg plate and movable under contro of said lever selectively to one position to actuate said geneva gear in one direction and to another position to actuate said geneva gear in the opposite direction upon reciprocation of said sliding plate.

7. in a calculating machine comprising an accumulator with add and subtract accumulator gears, actuator racks engageable selectively with said gears and subtotaling and totaling means, a credit balance transfer mechanism comprising a column transfer lever for each of a plurality of digits, the column transfer lever for the highest digit being movable according to whether the value stored in said accumulator is positive or negative, a rotatable square tooth wheel having alternate lands and recesses, means for converting movement of said column transfer lever for the highest digit into incremental movement of said square tooth wheel to position a land or a recess selectively at a predetermined inspection station, means for inspecting said square tooth gear to determine whether a land or a recess is positioned at said inspection station, and add and subtract control linkage means controlled by said inspecting means for causing either the add or subtract accumulator gears to engage selectively with the actuator racks upon the desired operation of subtotaling or totaling.

8. A credit balance transfer mechanism according to claim 7, in which said add and subtract control linkage comprises a geneva mechanism which rocks said gears in order to cause either the add or the subtract accumulator gears to engage selectively with the accumulator rack upon the desired operation of subtotaling or totaling.

i I I 

1. In a calculating machine, a credit balance transfer mechanism comprising an accumulator, a column transfer lever for each of a plurality of digits, means interconnecting the column transfer lever for the highest digit with the column transfer lever for the lowest digit, said column transfer lever for the highest digit being movable according to whether the value stored in said accumulator is positive or negative, a rotatable shaft, a ratchet wheel fixed on said shaft, means for converting movement of said column transfer lever for the highest digit into incremental rotary movement of said ratchet wheel and shaft, a rotatable member fixed on said shaft and having alternate lands and recesses, means for inspecting said rotary member for the presence of a land or recess at a predetermined position, said rotatable member being rotatable by said shaft, ratchet wheel and column transfer lever for the highest digit to position a land or a recess at said predetermined position according to whether the value stored in said accumulator is positive or negative and add and subtract control linkage controlled by said inspecting means.
 2. A credit balance transfer mechanism according to claim 1, in which said rotatable member is a gear having square teeth alternating with square recesses.
 3. A credit balance transfer mechanism according to claim 1, in which said inspecting means controls the selective engagement of an actuator rack with an add gear.
 4. A credit balance transfer mechanism according to claim 1, in which said inspecting means controls the selective engagement of an actuator rack with a subtraction gear.
 5. A credit balance transfer mechanism according to claim 1, in which said inspecting means comprises a movable lever, an abutment carried by said lever and means for moving said lever to bring said abutment into engagement with said rotatable member whereby said abutment engages a land or in a recess of said rotatable member according to the position of said rotatable member.
 6. A credit balance transfer mechanism according to claim 5, in which said add and subtract control linkage comprises a geneva gear, a reciprocable sliding plate and an actuating plate carried by said sliding plate and movable under control of said lever selectively to one position to actuate said geneva gear in one direction and to another position to actuate said geneva gear in the opposite direction upon reciprocation of said sliding plate.
 7. In a calculating machine comprising an accumulator with add and subtract accumulator gears, actuator racks engageable selectively with said gears and subtotaling and totaling means, a credit balance transfer mechanism comprising a column transfer lever for each of a plurality of digits, the column transfer lever for the highest digit being movable according to whether the value stored in said accumulator is positive or negative, a rotatable square tooth wheel having alternate lands and recesses, means for converting movement of said column transfer lever for the highest digit into incremental movement of said square tooth wheel to position a land or a recess selectively at a predetermined inspection station, means for inspecting said square tooth gear to determine whether a land or a recess is positioned at said inspection station, and add and subtract control linkage means controlled by said inspecting means for causing either the add or subtract accumulator gears to engage selectively with the actuator racks upon the desired operation of subtotaling or totaling.
 8. A credit balance transfer mechanism according to claim 7, in which said add and subtract control linkage comprises a geneva mechanism which rocks said gears in order to cause either the add or the subtract accumulator gears to engage selectively with the accumulator rack upon the desired operation of subtotAling or totaling. 